<form action="" method="post">
<input type="hidden" name="guardar" value="1"/>
<table>
<tr>
    <th>Usuario</th>
    <td><input name="usuario" /></td>
</tr>
<tr>
    <th>Pass</th>
    <td><input name="pass" required="" /></td>
</tr>
<tr>
    <th>Tipo</th>
    <td>
    <select name="tipo" >
        {html_options values=$option_id output=$option_descrip selected=$datos.tipo|default:"0"}
    </select>
    </td>
</tr>
<tr>
    <th colspan="2"><input type="submit" value="Agregar"/></th>
</tr>
</table>
</form>